Steam generator

ABSTRACT

There is provided a steam generator for a sustained supply, in a simple and easy way and without displacement, of steam that is as safe as in a steamed towel to the body skin or mucosa. The steam generator has a steam generation portion composed of a steam-generating composition containing a metal powder, a salt, and water, and an adhesive layer on the surface which is to be applied to the skin or mucosa. The steam-generating composition discharges steam as the metal powder is oxidized. In the steam generation portion, the steam-generating composition is held or sandwiched in a support so as to inhibit the movement of the steam-generating composition inside the steam generation portion, and the steam generation portion itself is formed into a sheet.

BACKGROUND OF THE INVENTION

[0001] 1. Field of the Invention

[0002] The present invention relates to a steam generator moisturizingthe skin of body parts such as the scalp, shoulders, neck, face, waste,buttocks, feet, hands, arms etc., or mucosa of eyes, nose, throat etc.,by supplying steam thereto, and more particularly to a steam generatorwhich makes it possible to cause the effective transepidermal absorptionof a cosmetic or pharmaceutical component by means of steam and heat.

[0003] 2. Description of the Related Art

[0004] Steam beautification devices, steamed towels and the like havebeen used to supply the appropriately heated steam to the skin, therebyenhancing circulation of blood in the skin as well as maintaining theskin in a desired moisturized state or bringing it into such state.

[0005] However, the steam beautification devices or steamed towelscannot be used at all times in any places. Moreover, the steambeautification devices are difficult to use on the body parts other thanthe face, and the problem associated with the steamed towels is that tooshort is a retention time in which a sufficient amount of steam can besupplied.

SUMMARY OF THE INVENTION

[0006] It is an object of the present invention to resolve theabove-described problems inherent to the prior art technology, to enablea sustained supply of safe steam, similar to that from steamed towels,to the skin or mucosa in a simple and easy way with a pleasantutilization feeling, and also to supply a cosmetic or pharmaceuticalcomponent simultaneously with the steam to the skin or mucosa, providefor effective permeation of the cosmetic or pharmaceutical componentthrough the skin or mucosa, and greatly enhance the utilizationefficiency thereof.

[0007] In order to attain the aforesaid object, the present inventionprovides a steam generator applicable to the skin or mucosa, which has asteam generation portion comprising a steam-generating compositioncontaining a metal powder, a salt, and water and discharging steam asthe metal powder is oxidized, wherein the steam-generating compositionis supported on or held in a support so as to inhibit the movement ofthe steam-generating composition in the steam generation portion, thesteam generation portion is formed into a sheet, and an adhesive layeris provided on the surface of the steam generator which is applied tothe skin or mucosa.

[0008] In the especially preferred embodiment of the steam generator, acosmetic or pharmaceutical component is contained in the adhesive layer.

[0009] The steam generator in accordance with the present invention isapplied to the skin or mucosa. The application of the steam generator tothe skin or mucosa as referred to herein, for example, means that thesteam generator is brought in contact with the skin or mucosa bysticking thereto or other measures.

[0010] Further, in accordance with the present invention, the steamdischarged from the steam generator includes both the steam resultingfrom the evaporation of water and formation of a gas phase and the steamhaving fine water droplets formed by the condensation of the gas.

[0011] In the steam generator in accordance with the present invention,a steam-generating composition containing a metal powder, a salt, andwater and discharging steam as the metal powder is oxidized is used inthe steam generation portion. Therefore, moisture and heat can besupplied to the skin or mucosa in any part of the body in a simple andeasy way and at any time.

[0012] Further, since an adhesive layer is provided on the surface ofthe steam generator which is applied to the skin or mucosa, the steamgenerator can be very easily stuck to the desired part on the skin ormucosa and no special holder is required.

[0013] In particular, if a cosmetic or pharmaceutical component isintroduced into the adhesive layer, since the steam brings the skin ormucosa and the adhesive layer in a hot and moist state, the permeationrate of the cosmetic or pharmaceutical component into the skin or mucosais increased and the utilization efficiency thereof can be increased.

[0014] Further, in the steam generator in accordance with the presentinvention, the steam-generating composition is held or sandwiched in thesupport so as to inhibit the movement of the steam-generatingcomposition in the steam generation portion. Therefore, the displacementof the steam-generating composition during maintenance or utilization ofthe steam generator and the formation of unevenness in the steamgeneration zone can be prevented and a problem associated with theunpleasant utilization feeling created by dangling lump-like portions ofthe steam-generating composition can be resolved. Moreover, because thesteam generation portion in the steam generator in accordance with thepresent invention is formed into a sheet, it can be used with goodsensation caused by sticking.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIGS. 1A and 1B are respectively a cross-sectional view and a planview of the steam generator;

[0016]FIGS. 2A, 2B, and 2C are respectively a cross-sectional view and aplan view of the steam generator and a schematic view of the steamgeneration portion;

[0017]FIGS. 3A and 3B are respectively a cross-sectional view and a planview of the steam generator;

[0018]FIGS. 4A and 4B are respectively a cross-sectional view and a planview of the steam generator;

[0019]FIG. 5 is a cross-sectional view of the steam generator;

[0020]FIG. 6 is a cross-sectional view of the steam generator; and

[0021]FIG. 7 is a cross-sectional view of the steam generator.

DETAILED DESCRIPTION OF THE INVENTION

[0022] The present invention will be described below in greater detailwith reference to the drawings. In the drawings, same or identicalstructural elements are denoted with the same symbols.

[0023]FIGS. 1A and 1B are respectively a cross-sectional view and a planview of a steam generator 10A which is an example of the presentinvention.

[0024] Steam generator 10A is constituted by a steam generation portion1A formed into a sheet, moisture-permeable sheets 5 a, 5 b successivelylaminated on the steam generating surface of steam generation portion1A, a moisture-impermeable sheet 6, an adhesive layer 7, a gas-permeablesheet 8 laminated on the other surface of steam generation portion 1A,and a sealing bag 9 enclosing and sealing all of the above components.When steam generator 10A is used, sealing bag 9 is ruptured, the contentthereof is removed therefrom, and adhesive layer 7 is stuck to the skinor mucosa. Further, openings H guiding the steam emitted from steamgeneration portion 1A to the skin or mucosa are provided inmoisture-impermeable sheet 6 and adhesive layer 7 of steam generator10A.

[0025] Steam generation portion 1A is composed of a steam-generatingcomposition 2 maintained in a supported condition on a support. Acomposition containing a metal powder (iron, aluminum, zinc, copper andthe like), a salt (sodium chloride, potassium chloride, calciumchloride, magnesium chloride and the like), and water, generating heatby oxidation of the metal powder as expressed by the following formula:

Fe+(¾)O₂+({fraction (3/2)})H₂O→Fe(OH)₃+96 kcal,

[0026] and emitting the water present in the system as steam is used asthe steam-generating composition 2. From the standpoint of costefficiency, reactivity, and safety, it is preferred that an iron powderbe used as the metal powder. Further, various components such aswater-retaining agents (vermiculite, calcium silicate, silica gel,silica-based porous substances, alumina, pulp, wood flour,water-absorbing polymer and the like) or reaction promoters (activecarbon, carbon black, graphite and the like) can be incorporated in thesteam-generating composition.

[0027] Steam generation portion 1A has a sheet-like structure in whichsteam-generating composition 2 is dispersed and retained inside thepores of a nonwoven fabric 3 having a multiplicity of pores, andnonwoven fabrics 4 a, 4 b are placed on both surfaces thereof so as toinhibit the movement and prevent the displacement of steam-generatingcomposition 2 in steam generation portion 1A. Such formation of steamgeneration portion 1A into a sheet can prevent the displacement of thesteam generation zone when steam generator 10A is used and can alsoimprove the sensation caused by sticking.

[0028] No limitation is placed on fiber materials in nonwoven fabric 3having a multiplicity of pores, but because of high water-retentionability thereof, it is preferred that cotton, pulp and the like be used.Furthermore, to provide the nonwoven fabric 3 with capability to retaina sufficient amount of the steam-generating composition, the nonwovenfabric 3 preferably has a porosity of no less than 60% and a basicweight of 10-300 g/m².

[0029] On the other hand, nonwoven fabrics 4 a, 4 b are provided toprevent leakage of steam-generating composition 2 retained in the poresof the above-described nonwoven fabric 3. Nonwoven fabrics which aremore dense than nonwoven fabric 3 and, for example, have a basic weightof 10-150 g/m² are preferably used as the nonwoven fabrics 4 a, 4 b.

[0030] A specific method for the manufacture of steam generation portion1A, for example, comprises the steps of laminating nonwoven fabric 3having a multiplicity of pores with comparatively dense nonwoven fabric4 a by using an adhesive, scattering a powdered component of theconstituents of steam-generating composition 2 over the upper surface ofnonwoven fabric 3, and applying vibrations or using vacuum suction sothat the steam-generating composition 2 is retained in the pores ofnonwoven fabric at a ratio of 500-8000 g/m². Then, nonwoven fabric 4 bis placed on the scattering surface and the laminate is thermallycompressed at a temperature of 70-250° C. under a linear pressure of0.5-100 kg/cm, and processed into a sheet-like product with a thicknessof 0.5-20 mm, preferably, 1-6 mm. Steam generation portion 1A is thenobtained by impregnating the sheet-like product with an aqueous solutioncontaining a salt among the constituents of steam-generating composition2.

[0031] The formulation of steam-generating composition 2 used in steamgenerator 11A has been employed as a heater generally termed as achemical body warmer. However, since the conventional chemical bodywarmers have been basically constructed as heating tools, they have beendesigned so as to have a proper gas permeability and to prevent theescape of water necessary for the reaction from the heat generator. Forthis purpose, the bags containing the heater of the chemical body warmerare not purposely constructed of materials that are permeable tomoisture, even though they are permeable to gas. For example, inJapanese Patent Application Laid-open No. H1-250252, a sheet was usedwhich had a moisture permeability of 10-400 g/m²·24 h, as determined byan ASTM method (E-96-80D method).

[0032] By contrast, in steam generator 10A, the steam-generatingcomposition 2 is positively used as a steam generation source, thisutilization mode thereof being markedly different from that of a similarcomposition in the conventional chemical body warmers. For that purpose,the layer of steam generation portion 1A at the skin or mucosa side isformed from a moisture-permeable material (includingmoisture-impermeable materials that as a whole are rendered moisturepermeable, for example, by forming holes therein), preferably, from amoisture-permeable material with a moisture permeability of no less than500 g/m²·24 h, more preferably, no less than 800 g/m²·24 h, still morepreferably, 1000-3000 g/m²·24 h, and even more preferably, 1400-2800g/m²·24 h. As a result, the amount of steam discharged from the surfaceof steam generator 10A which is applied to the skin or mucosa is no lessthan 0.002 mg/cm²·min, preferably, no less than 0.01 mg/cm²·min, andstill more preferably, no less than 0.5 mg/cm²·min. Here, the steamdischarge portion denotes a portion from which the steam is directlyemitted to the skin or mucosa, for example, the openings H of steamgenerator 10A in FIGS. 1A and 1B.

[0033] The amount of steam discharged from the surface of steamgenerator 10A which is applied to the skin or mucosa is determined bythe weight measurement method comprising the steps of removing the steamgenerator 10A from an atmosphere-shielding container under a roomtemperature environment (20° C., 65% RH), immediately placing it on atop-pan balance capable of weighing to the nearest 1 mg, and thenconducting measurements for 15 min. In this method, the amount of steamis calculated by the following Formula 1 in which Wt₀ (g) stands for theweight at the instant the measurement is started, Wt₁₅(g) stands for theweight after 15 min, and S (cm²) stands for the area of the portion ofthe steam generator surface which is applied to the skin or mucosa.

Amount of discharged steam (mg/cm ² ·min)=(Wt ₀ −Wt ₁₅)·1000/155  (1)

[0034] Furthermore, the amount of steam discharged from the steamdischarge portion of steam generator 10A is a numerical value(mg/cm²·min) of the amount of discharged steam determined by removingsteam generator 10A from an atmosphere-shielding container under a roomtemperature environment (20° C., 65% RH), immediately placing it in atransepidermal water evaporation measurement device (Evaporimeter;manufactured by ServoMed Co.), measuring humidity in the steam dischargeportion for 60 min, and conducting calculations from the maximum valueof humidity within 60 min.

[0035] In accordance with the present invention, it is preferred thateither the amount of discharged steam determined by the weightmeasurement method or the amount of discharged steam determined with thetransepidermal water evaporation measurement device be within theaforesaid range.

[0036] Furthermore, when adhesive layer 7 of steam generator 10Acomprises a water-soluble substrate, the adhesive layer 7 essentiallycontains a large amount of water and discharges steam by itself. Forthat reason, when the amount of steam discharged from steam generator10A is measured merely by the above-described weight measurement methodor with the transepidermal water evaporation measurement device, it isimpossible to determine whether the measured amount of steam has beencontained essentially in the adhesive layer 7 or in steam-generatingcomposition 2 and the measured amount of steam cannot serve as theindicator of steam discharge ability of steam generation portion 1A.Accordingly, when adhesive layer 7 comprises a water-soluble substrate,it is preferred that the amount of discharged steam is measured uponremoval of adhesive layer 7 from steam generator 10A.

[0037] Examples of materials for moisture-permeable sheets 5 a, 5 b insteam generator 11A include woven fabrics, nonwoven fabrics, paper,synthetic paper and the like obtained from fibers of one type or amixture of fibers of at least two types selected from synthetic fiberssuch as nylon, vinylon, polyester, rayon, acetate, acryl, polyethylene,polypropylene, poly(vinyl chloride) and the like, and natural fiberssuch as pulp, cotton, jute, silk, animal hair and the like. Furthermore,examples of materials suitable for moisture-impermeable sheet 6 havingopenings H provided therein include gas-impermeable films or sheetscomposed of polyethylene, polypropylene, polyamide, polyester,poly(vinyl chloride), poly(vinylidene chloride), polyurethane,polystyrene, saponified ethylene-vinyl acetate copolymer, ethylene-vinylacetate copolymer, natural rubber, regenerated rubber, synthetic rubberand the like, these films or sheets having holes provided therein.

[0038] On the other hand, gas-permeable sheet 8 laminated on the side ofsteam generation portion 1A that is opposite to the surface thereofwhich is applied to the skin or mucosa is preferably formed from amaterial with moisture permeability lower than that ofmoisture-permeable sheets 5 a, 5 b on the surface which is applied tothe skin or mucosa and moisture-impermeable sheet 6 having openings Hprovided therein. For example, it is preferably formed from a sheet witha comparatively low moisture permeability (for example, Japanese PatentApplication Laid-open No. H1-250252) that is generally used in chemicalbody warmers. As a result, steam from steam generation portion 1A can beeffectively discharged toward the skin or mucosa. Gas-permeable sheet 8is made gas permeable to supply oxygen to steam-generating composition 2therethrough. If the area of openings H or the mounting areas ofmoisture-impermeable sheet 6 and of adhesive sheet 7 were adjusted so asto supply the sufficient amount of oxygen from the surface ofapplication to the skin or mucosa to steam-generating composition 2,then a gas-impermeable sheet may be used instead of gas-permeable sheet8.

[0039] In the process for the manufacture of steam generator 10A, themoisture-permeable sheet 5 a and gas-permeable sheet 8 may beindividually laminated on steam generation portion 1A, but the steamgeneration portion 1A may also be enclosed in a bag having one surfacethereof composed of moisture-permeable sheet 5 a and the other surfacecomposed of gas-permeable sheet 8.

[0040] Moisture-permeable sheet 5 b is preferably provided with afunction of a temperature-adjusting material which controls with goodstability and reliability the temperature of steam discharged from thesurface of steam generator 10A that is applied to the skin or mucosa tono more than 50° C., preferably, no more than 45° C., even morepreferably, 38° C.-42° C. Accordingly, it is preferred that a nonwovenfabric or synthetic paper, even those selected from the above-describedmoisture-permeable sheets, be used as moisture-permeable sheet 5 b.

[0041] When the steam temperature is controlled in accordance with thepresent invention, the temperature measurement can be conducted byremoving the steam generator from an atmosphere-shielding containerunder a room temperature environment (20° C., 65% RH), placing the steamgenerator, with the steam generation surface facing down, on a foamedstyrol base, setting the temperature detection unit of a temperaturemeter (Thermorecorder RT-10; manufactured by Tabai Espec Corp.) on thesteam generation surface thereof so as to apply no weight to the steamgenerator, and measuring the temperature between the steam generationsurface and foamed styrol base. When the steam generator has openings Hon the surface which is applied to the skin or mucosa, as in steamgenerator 11A shown in FIGS. 1A and 1B, the temperature detector is setin the openings H.

[0042] When moisture-permeable sheet 5 b is composed of a nonwovenfabric or synthetic paper, their specific weight, thickness and the likeare determined appropriately according to the desired amount of steamdischarged from the surface of steam generator 10A because the nonwovenfabric or synthetic paper exhibits resistance to the passage of steamgenerated by steam generation portion 1A. Further, if the steamtemperature immediately after the discharge from steam generationportion 1A is no more than 50° C., preferably, no more than 45° C., thenthe need for nonwoven fabric or synthetic paper is obviated. Thethickness of adhesive layer 7 may be increased to control thetemperature of steam discharged from the surface of steam generator 10Athat is applied to the skin or mucosa to no more than 50° C.

[0043] Adhesive layer 7 is intentionally installed in the surface ofsteam generator 10A that is applied to the skin or mucosa rather than onthe outer edge of the application surface. As a result, steam generator10A can be attached to the desired application portion in a much moresimple and reliable manner than when adhesive layer 7 is simply presenton the outer edge of the application surface.

[0044] If necessary, a cosmetic or pharmaceutical component can beincorporated in adhesive layer 7. In such case, the cosmetic orpharmaceutical component can exert effect on the skin or mucosa, whichwas heated and moisturized by steam, from the adhesive layer 7 that isin a hot and moist state. Therefore, the permeation rate of the cosmeticor pharmaceutical component through the skin or mucosa is increased andthe utilization efficiency thereof is increased. The temperature andmoisture effect in such steam generator 10A is much higher than thatobtained when an adhesive layer having a cosmetic or pharmaceuticalcomponent incorporated therein was simply attached to a conventionalchemical body warmer (that is, when in a chemical body warmer with anadhesive layer backing, the steam was not specially supplied by heatingthe adhesive layer, and the skin or adhesive layer was moisturized bysweat from the skin), and the cosmetic or pharmaceutical component areeffectively caused to permeate through the skin or mucosa.

[0045] Further, a plurality of round openings H (Ha, Hb, Hc, Hd, He, Hf)are provided in adhesive layer 7. As a result, the steam discharged fromsteam generation portion 1A can be effectively guided to the skin ormucosa exclusively through openings H, as shown by an arrow. From thestandpoint of supplying a sufficient amount of steam and a cosmetic orpharmaceutical component to the skin or mucosa, the surface area ratioof openings H is preferably 0.1-50%, even more preferably, 0.5-30% ofthe entire surface over which the steam generator 10A is applied to theskin or mucosa.

[0046] No specific limitation is placed on the material constituting theadhesive layer 7, and adhesives composed of water-soluble orwater-insoluble substrate can be used. For example, an adhesivesubstrate composed of an aqueous gel obtained by using a crosslinkingagent of a water-soluble polymer (Japanese Patent Application Laid-openNo. H9-87171, paragraphs [0011]˜[0018]), aqueous adhesives, acrylicadhesives, rubber-based adhesives, silicone resin adhesives, adhesivesbased on natural polymers, cellulose polymers, starch polymers,synthetic polymers and the like (Japanese Patent Applications Laid-openNo. H9-12449, paragraphs [0012]˜[0018], and No. 7-233050, paragraphs[0009]˜[0024]), WO96/08245, page 5, line 18 to page 6, line 2) can beused.

[0047] Furthermore, examples of cosmetic or pharmaceutical componentsincorporated in adhesive layer 7 include blood circulation enhancerssuch as acidic mucopolysaccharides, chamomile, horse chestnut, ginkgo,hamamelis extract, Vitamin E, nicotinic acid derivatives, alkaloidcompounds and the like; swelling-reducing agents such as horse chestnut,flavone derivatives, naphthalenesulfonic acid derivatives, anthocyanins,Vitamin P, Calendula officinalis, concholytic acid, silanol, Terminalia,Visnaga, Majus and the like; slimming agents such as aminophylline, teaextract, caffeine, xanthine derivatives, inositol, dextransulfuric acidderivatives, horse chestnut, aescin, anthocyanidin, organoiodinecompounds, Hypericum erectum, Spiraea japonica, Equisetum arvense,Rosmarinus officinalis, gingsen, Hedera rhombea, thiomucase,hyaluronidase and the like; painkillers such as indometacin, diclofenac,dl-camphor, flurbiprofen, ketoprofen, cayenne pepper extract, piroxicam,felbinac, methyl salycilate, glycol salicylate and the like;moisture-retaining agents, for example, polyols such as glycerin,ceramides, collagens, and the like; peeling agents composed of proteasesuch as papain; depilating agents such as calcium thioglycolate; andautonomic regulating agents such as γ-oryzanol.

[0048] When protease is used as a peeling agent in adhesive layer 7, theprotease can be immobilized by the ordinary method employed inpreparation of immobilized enzymes. The catalytic activity of theprotease thus immobilized is increased by the steam and heat suppliedfrom steam-generating composition 2. Therefore, an old horny layerpresent on elbows, knees, heels and the like can be effectively removed.

[0049] Incorporating cosmetic or pharmaceutical components in adhesivelayer 7, as described above, can increase the utilization effectthereof. In particular, if a depilating agent is used, the steamsupplied from steam-generating composition 2 causes swelling andsoftening of the area surrounding hair root. As a result, painassociated with depilating can be greatly relieved in comparison withthe conventional methods for using the depilating agents and anexcellent depilating effect can be obtained.

[0050]FIGS. 2A and 2B are respectively a cross sectional view and a planview of steam generator 10B which is another embodiment of the presentinvention.

[0051] Common to the steam generator 10B and steam generator 10A shownin FIGS. 1A and 1B is that steam generation portion 1B composed ofnonwoven fabric 3 having a plurality of pores in which thesteam-generating composition 2 is dispersed and retained, but steamgenerator 10B differs from steam generator 10A in that both surfaces ofnonwoven fabric 3 where steam-generating composition 2 was dispersed andretained is not held between other nonwoven fabrics and in that thenumber of openings provided in gas-permeable sheet 6 and adhesive layer7 is large.

[0052] Steam generation portion 1B can be obtained by scattering a metalpowder, as a component of steam-generating composition 2, and applyingvibrations or using vacuum suction to retain the steam-generatingcomposition in the pores of nonwoven fabric 3, and then impregnatingwith a suspension composed of other components of steam-generatingcomposition 2. FIG. 2C is a schematic diagram of steam generationportion 1B thus obtained, this figure illustrating a state in whichsteam-generating composition 2 is retained in the pores between fibers 3x of nonwoven fabric.

[0053] A steam generator 10C shown in FIGS. 3A and 3B represents anembodiment in which, by contrast with steam generator 10A shown in FIGS.1A and 1B, the steam generation portion 1A and gas-permeable sheet 8 aredivided into a plurality of small units and openings H are provided overeach steam generation portion 1A.

[0054] Providing a plurality of steam generation portions 1A in onesteam generator 10C in the above-described manner can increase theflexibility of steam generator 10C and weaken a feeling of physicaldisorder when the steam generator is applied to the body. Further, whena plurality of steam generation portions 1A are provided, they may bebrought in contact to each other as shown in FIGS. 3A and 3B, or bonded,for example, by thermal fusion, or they may be separate from each other.

[0055] In a steam generator 11D shown in FIGS. 4A and 4B, by contrastwith steam generator 10A shown in FIGS. 1A and 1B, the adhesive layer 7is not provided on the peripheral edge of the surface over which thesteam generator 10D is applied to the skin or mucosa and the entiresteam discharged from steam generation portion 1A is supplied to theskin or mucosa from the peripheral edge of the surface over which thesteam generator 10D is applied to the skin or mucosa and from theopenings H provided in adhesive layer 7.

[0056] A steam generator 10E shown in FIGS. 5A and 5B differs from steamgenerator 10A shown in FIGS. 1A and 1B in that the openings H providedin adhesive layer 7 have a bandlike rather than round shape.

[0057] Thus, the present invention places no limitation on the shape ofopenings H that guide the steam discharged from steam generation portion1A to the skin or mucosa through the adhesive layer 7. Moreover, nolimitation is placed on the formation position of adhesive layer 7 onthe surface of steam generator which is applied to the skin or mucosa oron the surface area thereof. However, if adhesive layer 7 is formed overthe entire application surface, the amount of steam supplied to the skinor mucosa is reduced excessively. For this reason, the formation area ofadhesive layer 7 is preferably 50%˜99.9%, even more preferably,70%˜99.5% of the entire surface over which the steam generator isapplied to the skin or mucosa.

[0058] In a steam generator 10F shown in FIG. 6, a laminated materialcomposed of a laminate of a coating layer 2 a of a viscous liquid orliquid prepared by mixing a salt, water, and, if necessary, awater-retaining agent, as components of the steam-generatingcomposition, and a powder layer 2 b containing a metal power andlaminated thereon is provided on nonwoven fabric 4 serving as a support,this laminated material acting as a steam generation portion 1C in placeof steam generation portion 1A of steam generator 10A shown in FIGS. 1Aand 1B.

[0059] In a steam generator 10G shown in FIG. 7, a thin sheet formedfrom the steam-generating composition and a fibrous substance is used asa steam generation portion 1D in place of steam generation portion 1A ofsteam generator 10A shown in FIGS. 1A and 1B. Various natural orsynthetic fibers can be used as the fibrous substance, but from thestandpoint of gas permeability and cost, pulp is especially preferred.The thin sheet is preferably formed to have a water content of 5-60 wt.%, a metal powder ratio of 5-70 wt. %, and a thickness of 0.5-20 mm, inparticular, 1-6 mm.

[0060] Thus, in accordance with the present invention, the steamgeneration portion can be in a variety of forms, provided that thesteam-generating composition is supported on or held in a support so asto inhibit the movement of the steam-generating composition in the steamgeneration portion, and the steam generation portion is formed into asheet.

[0061] For example, in steam generator 10A shown in FIGS. 1A and 1B, atleast one of the following sheets: (1) cloth, (2) paper-like productsuch as paper, synthetic paper and the like, (3) porous films or poroussheets formed from plastics, natural rubbers, regenerated rubbers orsynthetic rubbers, (4) foamed plastics such as perforated urethane foamand the like, and (5) metal foils such as perforated aluminum foil, canbe used in place of the nonwoven fabric as the moisture-permeable sheet5 b serving to control the temperature of steam supplied to the skin ormucosa. Those temperature-adjusting materials may be used individuallyor as a laminate of a plurality of structural components. The laminationmethod and the way they are combined in case of lamination areappropriately determined so as to supply the preset amount of steam withpreset temperature to the skin or mucosa.

[0062] Furthermore, the particle size and specific surface area of themetal powder, such as iron powder, used in steam-generating composition2 and the amount of the metal powder present on an area of 1 cm² overwhich the steam generator is applied to the skin or mucosa may beappropriately adjusted to control the temperature of steam supplied tothe skin or mucosa.

[0063] A layer having a cosmetic or pharmaceutical component supportedtherein may be separately provided between the steam generation portion2 and adhesive layer 7, without incorporating the component intoadhesive layer 7.

EXAMPLES Example 1

[0064] Steam generator 10A of the embodiment shown in FIGS. 1A and 1Bwas prepared in the following manner.

[0065] First, an iron powder (RKH; manufactured by Dowa Iron Powder Co.,Ltd.) 50 wt. %, table salt 3 wt. %, water 27 wt. %, active carbon 5 wt.%, and vermiculite (manufactured by Shinsei Micron Co., Ltd.) 15 wt. %were mixed to give 20 g of steam-generating composition 2.

[0066] A nonwoven fabric 3 having a multiplicity of pores (OjiKinocloth; manufactured by Oji Paper Co., Ltd.) (22 cm×20 cm) and acomparatively dense nonwoven fabric 4 a (Elleair tissue; manufactured byDaio Paper Corp.) (22 cm×20 cm) were bonded with an ethylene-vinylacetate emulsion adhesive. Then, the aforesaid steam-generatingcomposition 2 was uniformly scattered with a nitrogen flow over nonwovenfabric 3 having a plurality of pores, an ethylene vinyl acetatecopolymer resin powder was scattered from the upper surface, andvertical vibrations were applied to the nonwoven fabric to retain thescattered materials in the pores of the nonwoven fabric. Nonwoven fabric4 b was then placed on the upper surface of nonwoven fabric 3, and theobtained laminated material was compressed and heated at a temperatureof 200° C. under a pressure of 100 kg/cm to obtain a sheet-like steamgeneration portion 1A having a thickness of 1.5 mm.

[0067] Steam generation portion 1A was cut to a size of 10×8 cm andinserted in a bag having one surface thereof composed of a gas-permeablesheet 8 (Breathlon; manufactured by Nitto Denko Co., Ltd.) and the othersurface composed of a moisture-permeable sheet 5 a (SWP; manufactured byMitsui Petrochemical Industries Co., Ltd.) A nonwoven fabric (SyntexV305; manufactured by Mitsui Petrochemical Industries Co., Ltd.) waslaminated as a moisture-permeable sheet 5 b on the bag surface at theside of the moisture-permeable sheet 5 a.

[0068] An adhesive composition of the recipe shown in Table 1 wasprepared. TABLE 1 Recipe of adhesive composition (units: wt. %)Indometacin 0.375 L-menthol 1 Crotamiton 3 Sodium polyacrylate 6Polyacrylic acid 2.5 Glycerin 25 Isopropyl myristate 2 Squalane 4Aluminum hydroxide gel 0.2 Soft amorphous silica 2 Purified waterBalance

[0069] This adhesive composition was uniformly coated on a PET film toform an adhesive layer that was then covered with a moisture-impermeablesheet 6 (Nitotack; manufactured by Nitto Denko Co., Ltd.) to obtain alaminated sheet (10 cm×14 cm) composed of adhesive layer 7 andmoisture-impermeable sheet 6. Holes with a diameter of 0.5 cm wereformed therein at a ratio of 6 holes/(10 cm×14 cm) as openings H, andthe laminated sheet was laid, by the moisture-impermeable sheet 6thereof, on the moisture-permeable sheet 5 b located on top of theabove-described steam generation portion 1A. Steam generator 10A thusobtained was sealed in a sealing bag 9.

Example 2

[0070] The steam generator 10B of the embodiment shown in FIGS. 2A, 2B,and 2C was fabricated in the following manner.

[0071] A powder prepared by homogeneously mixing 13 g of iron powder(RKH; manufactured by Dowa Iron Powder Co., Ltd.) and 2 g of activecarbon was sprinkled from above on a nonwoven fabric 3 having aplurality of pores (Oji Kinocloth; manufactured by Oji paper Col., Ltd.)(20 cm×20 cm) and subjected to vibrations to disperse and retain thepowder in the cloth. Then, 10 wt. % brine was scattered in a nitrogengas flow and uniformly impregnated by pressing with a roller to obtain asteam generation portion 1B.

[0072] Steam generator 10B was obtained by using the aforesaid steamgeneration portion 1B in place of steam generation portion 1A in theprocess for the manufacture of a steam generator in Example 1.

Example 3

[0073] Steam generator 10C shown in FIGS. 3A and 3B was fabricated inthe following manner.

[0074] First, six steam generation portions 1A with a size of the bottomsurface (nonwoven fabric 4 b) of 3 cm×3 cm were fabricated in the samemanner as in Example 1 and arranged in a row on a moisture-permeablesheet 5 b (10 cm×14 cm). Steam generator 10C was obtained by placing alaminate composed of adhesive layer 7 and moisture-impermeable sheet 6sheet identical to those of Example 1 and having the holes with adiameter of 1.0 cm formed therein at a ratio of 6 holes/(10 cm×14 cm) onmoisture-permeable sheet 5 b.

Example 4

[0075] Steam generator 10D shown in FIGS. 4A and 4B was fabricated.

[0076] The fabrication was conducted in the same manner as in Example 1,except that a sheet having a size of 10 cm×10 cm and openings H with adiameter of 1 cm arranged at a ratio of 4 openings/(10 cm×10 cm) wasused in place of the laminated sheet of adhesive layer 7 andmoisture-impermeable sheet 6.

Comparative Example 1

[0077] A steam generator of comparative example was obtained byinserting the steam-generating composition identical to that of Example1 in a bag (10 cm×14 cm) having one surface thereof composed ofgas-permeable sheet 8 (Breathlon; manufactured by Nitto Denko Co., Ltd.)and the other surface composed of moisture-permeable sheet 5 a (SWP;manufactured by Mitsui Petrochemical Industries Co., Ltd.) (Breathlon;manufactured by Nitto Denko Co., Ltd.), laying the moisture-permeablesheet 5 b on the surface of moisture-permeable sheet 5 a of the bag, andthen laying thereon a laminated sheet (10 cm×14 cm) composed of adhesivelayer 7 and moisture-impermeable sheet 6 identical to those of Example 1and provided with holes with a diameter of 1.0 cm at a ratio of 4holes/(10 cm×14 cm).

[0078] (Evaluation 1)

[0079] The steam generators obtained in Example 1 and ComparativeExample 1 were attached to the waist of several people and removed at atime shown in Table 2 and Table 3 after the attachment. The amount ofsteam discharged through each opening H (Ha, Hb, Hc, Hd, He, Hf) at theadhesive layer side was measured with the transepidermal waterevaporation measurement apparatus. The results are shown in Table 2 andTable 3. TABLE 2 Example 1 (units: g/m² hr) Time after attachment (min.)Opening 5 15 30 60 90 Ha 58 110 105 100 88 Hb 65 105 100 98 92 Hc 70 112102 98 87 Hd 70 115 98 105 90 He 62 108 104 95 88 Hf 60 100 110 102 85

[0080] TABLE 3 Comparative Example 1 (units: g/m² hr) Time afterattachment (min.) Opening 5 15 30 60 90 Ha 60 78 31 10≧ 10≧ Hb 70 55 2510≧ 10≧ Hc 68 34 12 10≧ 10≧ Hd 75 120 150 50   32   He 78 154 175 61  48   Hf 80 190 168 35   25  

[0081] The results shown in Tables 2 and 3 demonstrate that in the steamgenerator of Comparative Example 1, the steam-generating composition wasdisplaced in the course of attachment and, therefore, the steamgeneration portion was also displaced, whereas in the steam generator ofExample 1, the steam was discharged uniformly from all of the openings.

[0082] (Evaluation 2)

[0083] Example 1 and Comparative Example 1 were repeated as describedabove, except that the adhesive compositions used in the examples wereprepared by removing indometacin and crotamiton from the adhesivecomposition recipe shown in Table 1, and steam generators of Example 1band Comparative Example 1b were obtained.

[0084] Those steam generators were attached to the waist of severalpeople (a panel of 18 people), and a questionnaire study was conductedwith respect to a general feeling in usage, temperature, and unevenessin temperature. The results shown in Table 4 were obtained. Table 4demonstrates that the steam generator of Example, in which the steam wasdischarged uniformly from all of the openings, was superior to the steamgenerator of comparative example is terms of general feeling in usage.TABLE 4 General feeling in usage Example 1b: good 89%, no opinion 11%,poor 0% Comparative Example 1b: good 34%, no opinion 22%, poor 44%Temperature Example 1b: good 83%, no opinion 11%, poor 6% ComparativeExample 1b: good 39%, no opinion 39%, poor 22% Uneveness in TemperatureExample 1b: uneveness in temperature was felt 0%, no opinion 22%,uneveness in temperature was not felt 78% Comparative Example 1b:uneveness in temperature was felt 56%, no opinion 33%, uneveness intemperature was not felt 11%.

[0085] In accordance with the present invention, safe steam similar tothat from a steamed towel can be supplied continuously and withoutdisplacement to the skin or mucosa by using a simple structure and theutilization feeling is improved. Furthermore, with an embodiment inwhich a cosmetic or pharmaceutical component is incorporated in theadhesive layer, the effect of heat and moisture of the steam can greatlyimprove the utilization efficiency of the cosmetic or pharmaceuticalcomponent.

[0086] The entire disclosure of the spacification, claims, summary anddrawings of Japanese Patent Application No. 2000-252326 is herebyincorporated by reference.

What is claimed is:
 1. A steam generator applicable to the skin ormucosa, and having a steam generation portion which comprises asteam-generating composition containing a metal powder, a salt, andwater and discharges steam as the metal powder is oxidized, wherein thesteam-generating composition is held or sandwiched in a support so as toinhibit the movement of the steam-generating composition in the steamgeneration portion, the steam generation portion is formed into a sheet,and an adhesive layer is provided on the surface of the steam generatorwhich is applied to the skin or mucosa.
 2. The steam generator accordingto claim 1, wherein a cosmetic or pharmaceutical component is containedin the adhesive layer.
 3. The steam generator according to claim 1,wherein openings guiding the steam discharged from the steam generationportion to the skin or mucosa are provided in the adhesive layer.
 4. Thesteam generator according to claim 1, wherein the adhesive layer isprovided at least on the non-peripheral portion of the surface appliedto the skin or mucosa.
 5. The steam generator according to any one ofclaims 1 to 4, wherein the steam generation portion comprises thesteam-generating composition held in the pores of a nonwoven fabric. 6.The steam generator according to any one of claims 1 to 4, wherein thesteam generation portion comprises a paper sheet formed from thesteam-generating composition and a fibrous substance.
 7. The steamgenerator according to any one of claims 1 to 4, wherein the steamgeneration portion comprises a viscous liquid or liquid layer containinga salt and water, which is applied on a support, and a powder layer thatcomprises a metal powder and is laminated thereon.